Exhaust muffler for internal combustion engine



July 21, 1959 F. R. PERRY 2,895,562

EXHAUST MUFFLER FOR INTERNAL COMBUSTION ENGiNE Filed Aug. 12, 1955 FIG. I.

INVENTOR FRANK R. PERRY .ATTO R NEYS United States Patent O EXHAUST MUFFLER FOR INTERNAL COMBUSTION ENGINE Frank R. Perry, Los Angeles, Calif., assignor to Turco Products, Inc., a corporation of California Application August 12, 1955, Serial No. 527,937

'1 Claim. (Cl. 181--61) My invention has to do with exhaust mufflers for internal combustion engines and has, as one of its principal objects, the provision of a muffler incorporating novel and effective cooling means.

Another object is to provide a muffier utilizing control means operable to have the exhaust gases pass through the muffler in restricted form during low speeds and pass substantially uninterruptedly through the muffler at rela tively high speeds, the control means being operable automatically either in response to pressure in the muffler or at the motor intake manifold.

A need for providing effective cooling for mufflers is an old one and many attempts have been made to provide such cooling means. However, those attempts of which I am aware have been unsuccessful because they do not effect substantially uniform cooling throughout the axial length of the muffler and they have not been of such character as to provide maximum heat transfer from the shell of the muffler.

While I shall point out in the appended claim the features which I believe to be new in my muffler, I shall now, for the purpose of explaining my invention rather than for purposes of limitation, describe in detail presently preferred embodiments thereof, for which purpose I shall refer to the accompanying drawing wherein,

Fig. 1 is a side elevation with parts broken away for illustrative purposes;

Figs. 2, 3 and 4 are enlarged sections taken respectively on lines 2-2, 3-3 and 44 of Fig. 1;

Fig. 5 is a sectional view showing a modification of my invention; and

Fig. 6 is an enlarged elevational view taken on line 6-6 of Fig. 5.

Referring now to the drawing, the numeral 5 denotes the hollow cylindrical shell of the muffler, closed at its front or inlet end by a cap 6 and closed at its rear of outlet end by a cap 7.

The cap 6 has a hole 8 radially spaced from its center to receive an inlet tube 9 whose outer or right hand end may be suitably connected to the exhaust pipe of the motor (not shown), the tube having perforations 10 in its side wall. The outlet end cap 7 has a hole to pass a tailpipe 16. Tube 9 and the tailpipe 16 should be suitably secured to the respective end caps as by welding.

A ring 18 is secured on the inner end of the tailpipe, the periphery of the ring being secured to the inner surface of the shell as by a threaded stud 19, and carrying a butterfly valve 20 pivotally mounted in the ring by a shaft 22 suitably secured to the valve 20. The inner end of the shaft is journaled at 23 in the ring while the outer end portion of the shaft is journaled in the stud 19. A coiled leaf spring 25 is secured at one end to the shaft 22 by having an end portion of the spring engaged in a diametric slot 26 in the shaft, while the outer end of the sleeve is hooked selectively into one of a series of circumferentially spaced slots 27 (Fig. 3) provided in a cupshaped housing 28 supported by the stud 19. A cover cap 29 is frictionally fitted onto the housing 28. A stop screw 2,895,562 Patented July 21, 1959 30 is threaded through the ring 18 so that the butterfly valve may open only in one direction. The purpose of the series of slots 27 is to enable the tension of the spring to be adjusted. Typically, the tension of the spring may be adjusted to open when the pressure behind it in the mufller shell reaches about one pound per square inch. Rearwardly of the valve 20, the tailpipe is perforated at 32 before it emerges from the end cap 7. The tailpipe 16 is radially spaced from the center of cap 7 so that it is radially offset with relation to tube 9.

Fixed to the periphery of the shell 5, I provide two longitudinally spaced sleeves 35, 36 each presenting circumferentially arranged, V-shaped in cross-section, cooling members or walls 40, 41.

Each of the members 40, 41 is open at both ends so as to define, with the periphery of the mufiler shell, a triangular air passageway 42 open at each end, while the outer surfaces of contiguous ones of said members define V-shaped air passageways 43 open at each end. The members 40, 41 are preferably formed by corrugating a sheet of metal, wrapping the sheet around the shell, and welding the sheet to the outer surface of the mufiler shell.

As best shown in Fig. 4 the members 40, 41 are arranged in relatively staggered relationship so that the members are not in alignment with members 41.

The inlet ends of the members 41 are spaced longitudinally of the shell from the outlet ends of the members 40, while at the outlet ends of the members 40 I provide a deflector ring 45 secured to the shell as by welding.

Thus, air passing through passageways 42, 43 of the sleeve 35 of cooling members effectively cools the forward portion of the muffler shell, and is then deflected outwardly into atmosphere away from the inlet ends of passageways 42, 43 of members 41, while relatively fresh, cool air enters the inlet ends of the passageways 42, 43 of cooling members 41 to effectively cool the rear portion of the muffler shell and thence pass into the atmosphere. The members 40, 41 should be of such length in relation to the length of the muffler shell as to cover as much of the total length of the muffler shell as possible-that is, the spacing between the outlet end of members 40 and the inlet ends of members 41 should be only such as to permit the heated air to pass out of the cooling members 40 without any substantial portion of it entering the inlet ends of the passageways 42, 43 of members 41. Typically, this spacing should be about of the order of 2 /2.

By this construction, maximum heat transfer is effected from the mufiler shell, in that the air moving through passageways 42 directly cools the mulller shell as well as the members 40, 41 to which heat is transferred from the muffler shell, while the air passing along the passageways 43 further cools the members 40, 41 to enable them to transfer more heat from the mufiler shell. In this manner, the muffler shell is effectively cooled throughout its length.

In Figs. 5 and 6 I show a modified form of control for the butterfly valve. Here the valve is constructed as before described and is given like reference numerals except that instead of loading the valve member 20 with a spring as before described, I utilize the vacuum of the motor intake to open the valve.

Here I fix on the outer end of the shaft 22 a crank 50. Through a hole in the outer arm of the crank I extend an actuating rod 52 on the outer end of which I thread a nut 53. The inner end of the rod is fixed to a resilient diaphragm 55 mounted in a casing 56, which provides at the right of the diaphragm a vacuum chamber 57 and on the left of the diaphragm a chamber 58 open to atmosphere through hole 59. A vacuum line 60 communicates at one end with chamber 57 and communicates at its other end with the intake manifold of the internal combustion engine, now shown.

I claim:

In a muffier for an internal combustion engine, a hollow, cylindrical shell having an exhaust inlet at its inner end and an exhaust outlet at its outer end, means for cooling said shell comprising a pair of longitudinally spaced sleeves of corrugated cross section secured to and each extending about the periphery of said shell and defining therewith a plurality of open-ended air passageways extending longitudinally of said shell, the inlet ends 0 the passageways defined by the rear one of said sleeves and said shell being spaced longitudinally of said shell from the outlet ends of the passageways defined by the front one of said sleeves and said shell, and an annular air deflector carried by said shell between said sleeves.

References Cited in the file of this patent UNITED STATES PATENTS Desmond May 7, 1912 Losee May 22, 1917 Schrack Dec. 10, 1918 Schneebeli Dec. 27, 1921 Kingsley Mar. 2, 1937 Kurth Jan. 24, 1939 Deremer May 13, 1941 Deremer Dec. 1, 1953 Deremer Sept. 6, 1955 FOREIGN PATENTS France Aug. 6, 1934 France Feb. 6, 1939 Great Britain Dec. 24, 1941 

